The field of the invention is movable closures with cable drive and the present invention is particularly concerned with Bowden cable window lifts for the vertical displacement of windows in vehicles, particularly motor vehicles.
U.S. Pat. No. 3,890,743 and West German Published Application Nos. 2,616,331 and 2,644,213 show the state of this art and these disclosures are incorporated herein.
With the Bowden arrangement the spacer bar 8 shown in FIG. 1 of U.S. Pat. No. 3,890,743 is replaced by a guide rail having a U-shape cross-section and the fittings 14 and 15 are adapted to seat in the ends of this guide rail.
According to the prior art, Bowden cables consist of a closed cable loop which is wound on the one hand around a rotating drive drum and which on the other hand bears a drive means to which the window pane to be moved is connected directly or indirectly. Also, an essentially straight guide rail is part of the window lift means and the cable together with its drive means moves along this rail which in the installed condition in a motor vehicle is lined up parallel to the direction of motion of the pane. The cable passes through a Bowden traction sleeve in each region between the support plate of the drive drum and the upper and lower ends of the guide rail, each of these sleeves resting on the one hand on the plate and on the other hand at the upper and lower ends respectively of the guide rail. Such a Bowden cable window lift is known for example, from West German Published Application No. 26 16 331.
When such window lifts are installed in motor vehicles, it has been found both necessary and disadvantageous to bend the Bowden traction sleeves directly at the end of the guide rail and into a relatively short radius because there is no space available for a larger arc. As a result, there is constant risk that the Bowden sleeve will be bent excessively, that is, that it might kink.
To prevent such kinking, it has already been proposed to mount curved support members on the ends of the guide rail, over which the Bowden sleeves then are laid and which do not allow excessive bending of the sleeves. Such deflection members are described, for instance, in the West German Published Application No. 26 44 213.
However, there is a specific problem in mounting the support members to the guide rail. In the previously mentioned West German Published Application No. 26 44 213, the guide rail is a circular slotted tube and the support member is provided at its side facing this slotted tube with an annular groove engaged by the slotted tube. This means that the support member is merely set onto the slotted tube.
However, a drawback is incurred with this kind of mounting, in that the support member is not secured against being pulled off the slotted tube. Even though a window-lift system is closed per se and ordinarily is stressed by an integrated spring which keeps the support members in place on the slotted tube, it may happen, for instance in assembly, that a support member accidentally is pulled off the slotted tube. Also, the support members can best be slipped on only if the guide rail is circular in cross-section, for instance onto the known slotted tube.